The 465 series are generally considered to be excellent scopes. Tony was right, $600 is about the going rate, neither a bargain nor a ripoff (depending to a degree on the condition of the scope). When looking at a square wave, it is normal for the horizontal tops and bottoms to be brighter/thicker than the vertical segments. The linear speed of the beam when drawing the vertical lines is MANY times (sometimes hundreds or thousands of times) faster (in mm/second of beam travel) than when drawing the horizontal tops and bottoms, which results in a difference in the nature of the display. Barry Watzman ---------- From: Tony Duell [SMTP:ard@p850ug1.demon.co.uk] Sent: Monday, December 14, 1998 2:29 PM To: Discussion re-collecting of classic computers Subject: Re: tektronics 503 scope _Very_ nice portable 'scopes. I never owned one, but I've used the 465, 466, 453, etc and I like them a lot. That is about the 'going rate', I think. Not a bargain price IMHO, but not high either. And considering that's what you'd pay for a cheap new no-name 'scope, I'd much rather have the Tek. Does the thickness depend on the vertical attenuation (is it noise coming in from somewhere)? Can you resolve any structure to it by fiddling with the timebase (in other words could it be noise on the supply lines from somewhere - noise which almost certainly isn't at line frequency). What does the spot look like in X-Y mode with no signal? I can't think of another adjustment, but it's worth getting the service manual and going through the performance checks in there. And also checking for supply ripple, etc (yes, a second 'scope is worth having at this point...) -tony